/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.pulsar.functions;

import com.beust.jcommander.IStringConverter;
import com.beust.jcommander.JCommander;
import com.beust.jcommander.Parameter;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonParser;
import lombok.Builder;
import lombok.extern.slf4j.Slf4j;
import org.apache.pulsar.common.functions.FunctionConfig;
import org.apache.pulsar.common.io.SinkConfig;
import org.apache.pulsar.common.io.SourceConfig;
import org.apache.pulsar.common.nar.NarClassLoader;
import org.apache.pulsar.common.util.ObjectMapperFactory;
import org.apache.pulsar.common.util.Reflections;
import org.apache.pulsar.common.functions.AuthenticationConfig;
import org.apache.pulsar.functions.instance.InstanceConfig;
import org.apache.pulsar.functions.proto.Function;
import org.apache.pulsar.functions.runtime.process.ProcessRuntimeFactory;
import org.apache.pulsar.functions.runtime.RuntimeSpawner;
import org.apache.pulsar.functions.runtime.thread.ThreadRuntimeFactory;
import org.apache.pulsar.functions.secretsprovider.ClearTextSecretsProvider;
import org.apache.pulsar.functions.secretsprovider.SecretsProvider;
import org.apache.pulsar.functions.secretsproviderconfigurator.DefaultSecretsProviderConfigurator;
import org.apache.pulsar.functions.secretsproviderconfigurator.NameAndConfigBasedSecretsProviderConfigurator;
import org.apache.pulsar.functions.secretsproviderconfigurator.SecretsProviderConfigurator;
import org.apache.pulsar.functions.utils.FunctionCommon;
import org.apache.pulsar.functions.utils.FunctionConfigUtils;
import org.apache.pulsar.functions.utils.SinkConfigUtils;
import org.apache.pulsar.functions.utils.SourceConfigUtils;
import org.apache.pulsar.functions.utils.functioncache.FunctionCacheEntry;
import org.apache.pulsar.functions.utils.functions.FunctionUtils;
import org.apache.pulsar.functions.utils.functions.Functions;
import org.apache.pulsar.functions.utils.io.ConnectorUtils;
import org.apache.pulsar.functions.utils.io.Connectors;
import org.apache.pulsar.functions.worker.WorkerConfig;

import java.io.File;
import java.io.IOException;
import java.nio.file.Paths;
import java.util.LinkedList;
import java.util.List;
import java.util.Optional;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

import static org.apache.pulsar.common.functions.Utils.inferMissingArguments;

@Slf4j
public class LocalRunner {

    private final AtomicBoolean running = new AtomicBoolean(false);
    private final List<RuntimeSpawner> spawners = new LinkedList<>();
    private String narExtractionDirectory = NarClassLoader.DEFAULT_NAR_EXTRACTION_DIR;

    public enum RuntimeEnv {
        THREAD,
        PROCESS
    }

    public static class FunctionConfigConverter implements IStringConverter<FunctionConfig> {
        @Override
        public FunctionConfig convert(String value) {
            try {
                return ObjectMapperFactory.getThreadLocal().readValue(value, FunctionConfig.class);
            } catch (IOException e) {
                throw new RuntimeException("Failed to parse function config:", e);
            }
        }
    }

    public static class SourceConfigConverter implements IStringConverter<SourceConfig> {
        @Override
        public SourceConfig convert(String value) {
            try {
                return ObjectMapperFactory.getThreadLocal().readValue(value, SourceConfig.class);
            } catch (IOException e) {
                throw new RuntimeException("Failed to parse source config:", e);
            }
        }
    }

    public static class SinkConfigConverter implements IStringConverter<SinkConfig> {
        @Override
        public SinkConfig convert(String value) {
            try {
                return ObjectMapperFactory.getThreadLocal().readValue(value, SinkConfig.class);
            } catch (IOException e) {
                throw new RuntimeException("Failed to parse sink config:", e);
            }
        }
    }

    public static class RuntimeConverter implements IStringConverter<RuntimeEnv> {
        @Override
        public RuntimeEnv convert(String value) {
            return RuntimeEnv.valueOf(value);
        }
    }

    @Parameter(names = "--functionConfig", description = "The json representation of FunctionConfig", hidden = true, converter = FunctionConfigConverter.class)
    protected FunctionConfig functionConfig;
    @Parameter(names = "--sourceConfig", description = "The json representation of SourceConfig", hidden = true, converter = SourceConfigConverter.class)
    protected SourceConfig sourceConfig;
    @Parameter(names = "--sinkConfig", description = "The json representation of SinkConfig", hidden = true, converter = SinkConfigConverter.class)
    protected SinkConfig sinkConfig;
    @Parameter(names = "--stateStorageServiceUrl", description = "The URL for the state storage service (by default Apache BookKeeper)", hidden = true)
    protected String stateStorageServiceUrl;
    @Parameter(names = "--brokerServiceUrl", description = "The URL for the Pulsar broker", hidden = true)
    protected String brokerServiceUrl;
    @Parameter(names = "--clientAuthPlugin", description = "Client authentication plugin using which function-process can connect to broker", hidden = true)
    protected String clientAuthPlugin;
    @Parameter(names = "--clientAuthParams", description = "Client authentication param", hidden = true)
    protected String clientAuthParams;
    @Parameter(names = "--useTls", description = "Use tls connection\n", hidden = true, arity = 1)
    protected boolean useTls;
    @Parameter(names = "--tlsAllowInsecureConnection", description = "Allow insecure tls connection\n", hidden = true, arity = 1)
    protected boolean tlsAllowInsecureConnection;
    @Parameter(names = "--tlsHostNameVerificationEnabled", description = "Enable hostname verification", hidden = true, arity = 1)
    protected boolean tlsHostNameVerificationEnabled;
    @Parameter(names = "--tlsTrustCertFilePath", description = "tls trust cert file path", hidden = true)
    protected String tlsTrustCertFilePath;
    @Parameter(names = "--instanceIdOffset", description = "Start the instanceIds from this offset", hidden = true)
    protected int instanceIdOffset = 0;
    @Parameter(names = "--runtime", description = "Function runtime to use (Thread/Process)", hidden = true, converter = RuntimeConverter.class)
    protected RuntimeEnv runtimeEnv;
    @Parameter(names = "--secretsProviderClassName", description = "Whats the classname of secrets provider", hidden = true)
    protected String secretsProviderClassName;
    @Parameter(names = "--secretsProviderConfig", description = "Whats the config for the secrets provider", hidden = true)
    protected String secretsProviderConfig;

    private static final String DEFAULT_SERVICE_URL = "pulsar://localhost:6650";

    public static void main(String[] args) throws Exception {
        LocalRunner localRunner = LocalRunner.builder().build();
        JCommander jcommander = new JCommander(localRunner);
        jcommander.setProgramName("LocalRunner");

        // parse args by JCommander
        jcommander.parse(args);
        localRunner.start(true);
    }

    @Builder
    public LocalRunner(FunctionConfig functionConfig, SourceConfig sourceConfig, SinkConfig sinkConfig, String
            stateStorageServiceUrl, String brokerServiceUrl, String clientAuthPlugin, String clientAuthParams,
                       boolean useTls, boolean tlsAllowInsecureConnection, boolean tlsHostNameVerificationEnabled,
                       String tlsTrustCertFilePath, int instanceIdOffset, RuntimeEnv runtimeEnv,
                       String secretsProviderClassName, String secretsProviderConfig) {
        this.functionConfig = functionConfig;
        this.sourceConfig = sourceConfig;
        this.sinkConfig = sinkConfig;
        this.stateStorageServiceUrl = stateStorageServiceUrl;
        this.brokerServiceUrl = brokerServiceUrl;
        this.clientAuthPlugin = clientAuthPlugin;
        this.clientAuthParams = clientAuthParams;
        this.useTls = useTls;
        this.tlsAllowInsecureConnection = tlsAllowInsecureConnection;
        this.tlsHostNameVerificationEnabled = tlsHostNameVerificationEnabled;
        this.tlsTrustCertFilePath = tlsTrustCertFilePath;
        this.instanceIdOffset = instanceIdOffset;
        this.runtimeEnv = runtimeEnv;
        this.secretsProviderClassName = secretsProviderClassName;
        this.secretsProviderConfig = secretsProviderConfig;

        java.lang.Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                LocalRunner.this.stop();
            }
        });
    }

    public synchronized void stop() {
        running.set(false);
        log.info("Shutting down the localrun runtimeSpawner ...");
        for (RuntimeSpawner spawner : spawners) {
            spawner.close();
        }
        spawners.clear();
    }

    public void start(boolean blocking) throws Exception {
        List<RuntimeSpawner> local = new LinkedList<>();
        synchronized (this) {
            if (running.get() == true) {
                throw new IllegalArgumentException("Pulsar Function local run already started!");
            }

            Function.FunctionDetails functionDetails;
            String userCodeFile;
            int parallelism;
            if (functionConfig != null) {
                FunctionConfigUtils.inferMissingArguments(functionConfig, true);
                ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
                parallelism = functionConfig.getParallelism();
                if (functionConfig.getRuntime() == FunctionConfig.Runtime.JAVA) {
                    userCodeFile = functionConfig.getJar();

                    // if code file not specified try to get location of the code based on class.
                    if (userCodeFile == null && functionConfig.getClassName() != null) {
                        userCodeFile = Thread.currentThread().getContextClassLoader()
                                .loadClass(functionConfig.getClassName())
                                .getProtectionDomain().getCodeSource().getLocation().getFile();
                    }

                    boolean isBuiltin = !org.apache.commons.lang3.StringUtils.isEmpty(functionConfig.getJar()) && functionConfig.getJar().startsWith(org.apache.pulsar.common.functions.Utils.BUILTIN);
                    if(isBuiltin){
                        WorkerConfig workerConfig = WorkerConfig.load(System.getenv("PULSAR_HOME") + "/conf/functions_worker.yml");
                        Functions functions = FunctionUtils.searchForFunctions(System.getenv("PULSAR_HOME") + workerConfig.getFunctionsDirectory().replaceFirst("^.", ""));
                        String functionType = functionConfig.getJar().replaceFirst("^builtin://", "");
                        userCodeFile = functions.getFunctions().get(functionType).toString();
                    }
                     
                    if (org.apache.pulsar.common.functions.Utils.isFunctionPackageUrlSupported(userCodeFile)) {
                        File file = FunctionCommon.extractFileFromPkgURL(userCodeFile);
                        classLoader = FunctionConfigUtils.validate(functionConfig, file);
                    } else {
                        File file = new File(userCodeFile);
                        if (!file.exists()) {
                            throw new RuntimeException("User jar does not exist");
                        }
                        classLoader = FunctionConfigUtils.validate(functionConfig, file);
                    }

                } else if (functionConfig.getRuntime() == FunctionConfig.Runtime.GO) {
                    userCodeFile = functionConfig.getGo();
                } else if (functionConfig.getRuntime() == FunctionConfig.Runtime.PYTHON) {
                    userCodeFile = functionConfig.getPy();
                } else {
                    throw new UnsupportedOperationException();
                }

                functionDetails = FunctionConfigUtils.convert(functionConfig, classLoader);
            } else if (sourceConfig != null) {
                inferMissingArguments(sourceConfig);
                userCodeFile = sourceConfig.getArchive();

                // if code file not specified try to get location of the code based on class.
                if (userCodeFile == null && sourceConfig.getClassName() != null) {
                    userCodeFile = Thread.currentThread().getContextClassLoader()
                            .loadClass(sourceConfig.getClassName())
                            .getProtectionDomain().getCodeSource().getLocation().getFile();
                }

                if (userCodeFile == null) {
                    userCodeFile = Thread.currentThread().getContextClassLoader()
                            .loadClass(LocalRunner.class.getName())
                            .getProtectionDomain().getCodeSource().getLocation().getFile();
                }

                String builtInSource = isBuiltInSource(userCodeFile);
                if (builtInSource != null) {
                    sourceConfig.setArchive(builtInSource);
                }
                parallelism = sourceConfig.getParallelism();

                if (org.apache.pulsar.common.functions.Utils.isFunctionPackageUrlSupported(userCodeFile)) {
                    File file = FunctionCommon.extractFileFromPkgURL(userCodeFile);
                    functionDetails = SourceConfigUtils.convert(sourceConfig, SourceConfigUtils.validate(sourceConfig, null, file, narExtractionDirectory, true));

                } else {
                    File file = new File(userCodeFile);
                    if (!file.exists()) {
                        throw new RuntimeException("Source archive (" + userCodeFile + ") does not exist");
                    }
                    functionDetails = SourceConfigUtils.convert(sourceConfig, SourceConfigUtils.validate(sourceConfig, null, file, narExtractionDirectory, true));
                }
            } else if (sinkConfig != null) {
                inferMissingArguments(sinkConfig);
                userCodeFile = sinkConfig.getArchive();

                // if code file not specified try to get location of the code based on class.
                if (userCodeFile == null && sinkConfig.getClassName() != null) {
                    userCodeFile = Thread.currentThread().getContextClassLoader()
                            .loadClass(sinkConfig.getClassName())
                            .getProtectionDomain().getCodeSource().getLocation().getFile();
                }

                String builtInSink = isBuiltInSink(userCodeFile);
                if (builtInSink != null) {
                    sinkConfig.setArchive(builtInSink);
                }
                parallelism = sinkConfig.getParallelism();

                if (org.apache.pulsar.common.functions.Utils.isFunctionPackageUrlSupported(userCodeFile)) {
                    File file = FunctionCommon.extractFileFromPkgURL(userCodeFile);
                    functionDetails = SinkConfigUtils.convert(sinkConfig, SinkConfigUtils.validate(sinkConfig, null, file, narExtractionDirectory, true));
                } else {
                    File file = new File(userCodeFile);
                    if (!file.exists()) {
                        throw new RuntimeException("Sink archive does not exist");
                    }
                    functionDetails = SinkConfigUtils.convert(sinkConfig, SinkConfigUtils.validate(sinkConfig, null, file, narExtractionDirectory,  true));
                }
            } else {
                throw new IllegalArgumentException("Must specify Function, Source or Sink config");
            }

            if (System.getProperty(FunctionCacheEntry.JAVA_INSTANCE_JAR_PROPERTY) == null) {
                System.setProperty(FunctionCacheEntry.JAVA_INSTANCE_JAR_PROPERTY,
                        LocalRunner.class.getProtectionDomain().getCodeSource().getLocation().getFile());
            }

            AuthenticationConfig authConfig = AuthenticationConfig.builder().clientAuthenticationPlugin
                    (clientAuthPlugin)
                    .clientAuthenticationParameters(clientAuthParams).useTls(useTls)
                    .tlsAllowInsecureConnection(tlsAllowInsecureConnection)
                    .tlsHostnameVerificationEnable(tlsHostNameVerificationEnabled)
                    .tlsTrustCertsFilePath(tlsTrustCertFilePath).build();

            String serviceUrl = DEFAULT_SERVICE_URL;
            if (brokerServiceUrl != null) {
                serviceUrl = brokerServiceUrl;
            }

            if ((sourceConfig != null || sinkConfig != null || functionConfig.getRuntime() == FunctionConfig.Runtime.JAVA)
                    && (runtimeEnv == null || runtimeEnv == RuntimeEnv.THREAD)) {
                // By default run java functions as threads
                startThreadedMode(functionDetails, parallelism, instanceIdOffset, serviceUrl,
                        stateStorageServiceUrl, authConfig, userCodeFile);
            } else {
                startProcessMode(functionDetails, parallelism, instanceIdOffset, serviceUrl,
                        stateStorageServiceUrl, authConfig, userCodeFile);
            }
            local.addAll(spawners);
        }

        if (blocking) {
            for (RuntimeSpawner spawner : local) {
                spawner.join();
                log.info("RuntimeSpawner quit because of", spawner.getRuntime().getDeathException());
            }
        }
    }

    private void startProcessMode(org.apache.pulsar.functions.proto.Function.FunctionDetails functionDetails,
                                           int parallelism, int instanceIdOffset, String serviceUrl,
                                           String stateStorageServiceUrl, AuthenticationConfig authConfig,
                                           String userCodeFile) throws Exception {
        SecretsProviderConfigurator secretsProviderConfigurator = getSecretsProviderConfigurator();
        try (ProcessRuntimeFactory containerFactory = new ProcessRuntimeFactory(
                serviceUrl,
                stateStorageServiceUrl,
                authConfig,
                null, /* java instance jar file */
                null, /* python instance file */
                null, /* log directory */
                null, /* extra dependencies dir */
                narExtractionDirectory, /* nar extraction dir */
                secretsProviderConfigurator,
                false, Optional.empty(), Optional.empty())) {

            for (int i = 0; i < parallelism; ++i) {
                InstanceConfig instanceConfig = new InstanceConfig();
                instanceConfig.setFunctionDetails(functionDetails);
                // TODO: correctly implement function version and id
                instanceConfig.setFunctionVersion(UUID.randomUUID().toString());
                instanceConfig.setFunctionId(UUID.randomUUID().toString());
                instanceConfig.setInstanceId(i + instanceIdOffset);
                instanceConfig.setMaxBufferedTuples(1024);
                instanceConfig.setPort(FunctionCommon.findAvailablePort());
                instanceConfig.setClusterName("local");
                if (functionConfig != null) {
                    instanceConfig.setMaxPendingAsyncRequests(functionConfig.getMaxPendingAsyncRequests());
                }
                RuntimeSpawner runtimeSpawner = new RuntimeSpawner(
                        instanceConfig,
                        userCodeFile,
                        null,
                        containerFactory,
                        30000);
                spawners.add(runtimeSpawner);
                runtimeSpawner.start();
            }
            Timer statusCheckTimer = new Timer();
            statusCheckTimer.scheduleAtFixedRate(new TimerTask() {
                @Override
                public void run() {
                    CompletableFuture<String>[] futures = new CompletableFuture[spawners.size()];
                    int index = 0;
                    for (RuntimeSpawner spawner : spawners) {
                        futures[index] = spawner.getFunctionStatusAsJson(index);
                        index++;
                    }
                    try {
                        CompletableFuture.allOf(futures).get(5, TimeUnit.SECONDS);
                        for (index = 0; index < futures.length; ++index) {
                            String json = futures[index].get();
                            Gson gson = new GsonBuilder().setPrettyPrinting().create();
                            log.info(gson.toJson(new JsonParser().parse(json)));
                        }
                    } catch (Exception ex) {
                        log.error("Could not get status from all local instances");
                    }
                }
            }, 30000, 30000);
            java.lang.Runtime.getRuntime().addShutdownHook(new Thread() {
                public void run() {
                    statusCheckTimer.cancel();
                }
            });
        }
    }


    private void startThreadedMode(org.apache.pulsar.functions.proto.Function.FunctionDetails functionDetails,
                                           int parallelism, int instanceIdOffset, String serviceUrl,
                                           String stateStorageServiceUrl, AuthenticationConfig authConfig,
                                           String userCodeFile) throws Exception {
        SecretsProvider secretsProvider;
        if (secretsProviderClassName != null) {
            secretsProvider = (SecretsProvider) Reflections.createInstance(secretsProviderClassName, ClassLoader.getSystemClassLoader());
            Map<String, String> config = null;
            if (secretsProviderConfig != null) {
                config = (Map<String, String>)new Gson().fromJson(secretsProviderConfig, Map.class);
            }
            secretsProvider.init(config);
        } else {
            secretsProvider = new ClearTextSecretsProvider();
        }
        ThreadRuntimeFactory threadRuntimeFactory = new ThreadRuntimeFactory("LocalRunnerThreadGroup",
                serviceUrl,
                stateStorageServiceUrl,
                authConfig,
                secretsProvider,
                null, narExtractionDirectory, null);
        for (int i = 0; i < parallelism; ++i) {
            InstanceConfig instanceConfig = new InstanceConfig();
            instanceConfig.setFunctionDetails(functionDetails);
            // TODO: correctly implement function version and id
            instanceConfig.setFunctionVersion(UUID.randomUUID().toString());
            instanceConfig.setFunctionId(UUID.randomUUID().toString());
            instanceConfig.setInstanceId(i + instanceIdOffset);
            instanceConfig.setMaxBufferedTuples(1024);
            instanceConfig.setPort(FunctionCommon.findAvailablePort());
            instanceConfig.setClusterName("local");
            if (functionConfig != null) {
                instanceConfig.setMaxPendingAsyncRequests(functionConfig.getMaxPendingAsyncRequests());
            }
            RuntimeSpawner runtimeSpawner = new RuntimeSpawner(
                    instanceConfig,
                    userCodeFile,
                    null,
                    threadRuntimeFactory,
                    30000);
            spawners.add(runtimeSpawner);
            runtimeSpawner.start();
        }
    }

    private String isBuiltInSource(String sourceType) throws IOException {
        // Validate the connector source type from the locally available connectors
        Connectors connectors = getConnectors();

        String source = sourceType.replaceFirst("^builtin://", "");
        if (connectors.getSources().containsKey(source)) {
            // Source type is a valid built-in connector type. For local-run we'll fill it up with its own archive path
            return connectors.getSources().get(source).toString();
        } else {
            return null;
        }
    }

    private String isBuiltInSink(String sinkType) throws IOException {
        // Validate the connector source type from the locally available connectors
        Connectors connectors = getConnectors();

        String sink = sinkType.replaceFirst("^builtin://", "");
        if (connectors.getSinks().containsKey(sink)) {
            // Source type is a valid built-in connector type. For local-run we'll fill it up with its own archive path
            return connectors.getSinks().get(sink).toString();
        } else {
            return null;
        }
    }

    private Connectors getConnectors() throws IOException {
        // Validate the connector source type from the locally available connectors
        String pulsarHome = System.getenv("PULSAR_HOME");
        if (pulsarHome == null) {
            pulsarHome = Paths.get("").toAbsolutePath().toString();
        }
        String connectorsDir = Paths.get(pulsarHome, "connectors").toString();
        return ConnectorUtils.searchForConnectors(connectorsDir, narExtractionDirectory);
    }

    private SecretsProviderConfigurator getSecretsProviderConfigurator() {
        SecretsProviderConfigurator secretsProviderConfigurator;
        if (secretsProviderClassName != null) {
            Map<String, String> config = null;
            if (secretsProviderConfig != null) {
                config = (Map<String, String>)new Gson().fromJson(secretsProviderConfig, Map.class);
            }
            secretsProviderConfigurator = new NameAndConfigBasedSecretsProviderConfigurator(secretsProviderClassName, config);
        } else {
            secretsProviderConfigurator = new DefaultSecretsProviderConfigurator();
        }
        return secretsProviderConfigurator;
    }
}
